Q: There is a long list of invasive species imported to North America, but are there any such exports?
A: There are several well-known animal species native to North America that are considered invaders in Europe and elsewhere, and some plant species as well, but on the whole, North America has more imports than exports.
A 2014 study found evidence that the reason for the imbalance is the longer evolutionary history of Old World species. The study, in the journal Global Ecology and Biogeography, found that successful invaders tended to come from regions with a high genetic diversity of competing species and a long history of successful competition.
One of the troublesome animal travelers from North America to Europe and elsewhere is the Eastern gray squirrel, which is now so populous in Britain and Italy that the smaller and less aggressive native red squirrel is locally extinct. The gray squirrel was taken to Europe as a pet and made itself at home in the wild.
Other invaders include the largemouth bass and the North American bullfrog, which has spread from the central and eastern United States and Canada to South America, Europe and Asia.
As for plants, one interesting case is the Hudson pear, a cactus from Mexico. It became a pest in the Australian province of New South Wales, where opal miners planted it to provide thorny barriers around their mining claims.
ActiveStyle on 06/19/2017